1. Field of the Invention
The invention relates to phase-locked loops, especially those including a quartz oscillator as variable-frequency, voltage-controlled oscillator.
2. Description of the Related Art
A phase-locked loop conventionally includes a phase comparator, the two inputs of which respectively receive an external signal generally having the function of synchronizing signal, and an internal signal to be synchronized, coming from the output signal of the voltage-controlled oscillator. The phase comparator is furthermore looped back at the output of this oscillator by use of a filter. Such a phase-locked loop is activated upon the coincidence of the transitions between the synchronizing signal and the signal to be synchronized.
The general object of the invention is to promote activation of a phase-locked loop by accelerating the synchronization of the two external and internal signals.